Fig 4. rtfA regulates protease activity.

Aspergillus fumigatus wild type (WT), ΔrtfA, complementation (com), and overexpression rtfA (OErtfA) strains were point-inoculated on GMM containing 5% skim milk (Difco) and incubated at 37°C. (A) Quantification of proteolytic activity is shown as measured by Azo-casein assay after four days of growth. Different letters above the bars indicate significantly different values (p ≤ 0.05). Error bars represent standard error. (B) Degradation halos (indicated with arrows) at the edge of the colonies growing on skim milk agar plates for four days.